Upgrade

The entire Janghang Line is being electrified, double-tracked, and upgraded for higher speeds with a straighter alignment. Work started in 1997 from Cheonan.^[2] By the end of 2008, the new alignment was in service from Cheonan via Asan and Hongseong to Sinseong, from Jupo to Nampo, and from Ganchi to Janghang,^[3] and electrification was put in service on the first 19.4 km (12.1 mi) between Cheonan and Sinchang, after Asan, on December 15, 2008.^[4] The 17.1 km (10.6 mi) section near Janghang, opened in December 2007, also linked up the Janghang Line with the previously isolated Iksan-Gunsan line via a new bridge over the Geum River, with alignment built for two tracks but initially only one track was laid.^[2] In 2010, the remaining sections were slated to be completed by 2018, but complete double-tracking and electrification was no longer planned on the short term due to expected low demand.^[3] The realigned 14.2 km (8.8 mi) Nampo-Ganchi section, including the relocated Ungcheon station, was opened on January 5, 2021.^[5] As of April 2023, the double-tracking of the Sinchang-Hongseong section was 85% completed and expected to be opened in the second half of 2024.^[6] Also as of April 2023, the double-tracking of the Hongseong-Daeya section, including the 18.8 km (11.7 mi) Sinseong-Jupo realignment that was scheduled to begin construction in 2023, was in advanced planning, with a 2027 completion targeted.^[6]

The Janghang Line will link up with the Seohae Line at Hongseong station. The Seohae Line will connect Hongseong to Hwaseong in Gyeonggi-do when it opens in the second half of 2024.^[6] It will be connected to southern extension of the Sosa–Wonsi Line and Sinansan Line. Seohae Line will serve 250 km/h (155 mph) speed, which will dramatically reduce travel time between Seoul and Hongseong.

Seoul Metropolitan Subway

Seoul Subway's Line 1 services run on the line between Cheonan–Sinchang stations.